WO2001029055A2

WO2001029055A2 - Novel oligosaccharides, preparation method and pharmaceutical compositions containing same

Info

Publication number: WO2001029055A2
Application number: PCT/FR2000/002897
Authority: WO
Inventors: Pierre Mourier; Elisabeth Perrin; Christian Viskov; Jean-Marie Stutzmann; Florence Wahl
Original assignee: Aventis Pharma S.A.
Priority date: 1999-10-22
Filing date: 2000-10-18
Publication date: 2001-04-26
Also published as: DK1226148T3; SK287459B6; CY1112274T1; HU229385B1; HK1050535A1; MXPA02003945A; NO20021859L; YU29802A; EA004046B1; CA2388369C; CZ303255B6; JP2003512385A; SK5272002A3; CZ20021385A3; ATE534656T1; AU7930200A; PL363052A1; KR20070087263A; HUP0203821A3; EP1226148A2

Abstract

The invention concerns oligosaccharides of formula (I), their mixtures, their diastereomers, methods for preparing them and pharmaceutical compositions containing them.

Description

NEW OLIGOSACCHARIDES. THEIR PREPARATION AND THE PHARMACEUTICAL COMPOSITIONS CONTAINING THEM

The present invention relates to oligosaccharides of formula:

their mixtures, their diastereoisomers, their preparation process and the pharmaceutical compositions containing them.

Sulfated disaccharides having a reducing end with a 1,6-anhydro structure have been described by H.P. WESSEL, J. Carbohydrate Chemistry, 11 (8), 1039-1052 (1992); no pharmacological activity is mentioned for these.

Sulfated trisaccharides comprising a 1,6-anhydro motif have also been described in patent EP84999 and by Y. ICHIKAWA et al., Carbohydr. Res, 141, 273-282 (1985) as intermediates for the preparation of higher oligosaccharides. These trisaccharides have a weak anti-Xa activity.

In formula (I) n is an integer from 0 to 25, Ri, R, R * and R ₅ , identical or different, represent a hydrogen atom or an SO M radical, R ₂ and R ₆ , identical or different , represent a hydrogen atom or an SO ₃ M or COCH ₃ radical and M is sodium, calcium, magnesium or potassium.

These oligosaccharides thus contain an even number of saccharides.

In formula (I), ₄ is preferably a hydrogen atom. Preferably, n is an integer from 0 to 10 and, in particular from 0 to 6 and even more particularly from 1 to 6.

The oligosaccharides of formula (I) can be prepared by the action of an alkali metal hydroxide or of quaternary ammonium on oligosaccharides of formula:

in which n is an integer from 0 to 25, Ri, R, R and R ₅ , identical or different, represent a hydrogen atom or an SO ₃ M radical, R ₂ and R ₆ , identical or different, represent an atom hydrogen or an SO ₃ M or COCH ₃ radical and M is sodium, calcium, magnesium or potassium, or a mixture of these.

This reaction is carried out in an aqueous medium, at a temperature of 40 to 80 ° C, at a pH of 10 to 13.

As alkali metal hydroxide which can be used, there may be mentioned sodium hydroxide, potassium hydroxide, lithium hydroxide and cesium hydroxide.

As quaternary ammonium hydroxide which can be used, mention may be made of tetrabutylammonium hydroxide.

The quantity of alkali metal hydroxide or of quaternary ammonium must be sufficient for the pH of the reaction medium to remain stable throughout the duration of the reaction. It is thus necessary to continuously add throughout the reaction the alkali metal or quaternary ammonium hydroxide. Preferably, the alkali metal or quaternary ammonium hydroxide is in the form of an aqueous solution of 1 to 5%.

Preferably, the reaction is carried out at a temperature of 60 to 70 ° C.

Advantageously, the reaction pH is from 1 1 to 12.5.

The reaction is stopped by acidification of the reaction medium, for example by addition of acidic resin such as Amberlite IR120 ^R resin (Fluka).

The oligosaccharides of formula (I) can be optionally purified by gel permeation chromatography of the polyacrylamide-agarose type such as that sold under the brand Ultrogel ACA202 ^R (Biosepra) according to the protocol described below for the separation of the intermediate oligosaccharides of formula (II). The oligosaccharides of formula (I) for which n is 0 or 1 can also optionally be purified on an alumina column with a water-ethanol mixture as eluent.

The intermediate oligosaccharides of formula (II) and their mixtures can be obtained by separation by gel chromatography of a mixture of oligosaccharides (III) obtained by enzymatic depolymerization of heparin or basic depolymerization of the benzyl ester of heparin or a benzyl ester of hemisinesis of hemisynthesis.

This chromatography is carried out on columns filled with polyacrylamide-agarose type gel such as that sold under the brand Ultrogel ACA202 ^R (Biosepra). Preferably, a battery of columns of agarose polyacrylamide gel is used. The number of columns used is adapted according to the volume, the gel and the oligosaccharides to be separated. The mixture is eluted with a solution containing a phosphate buffer and sodium chloride. Preferably, the phosphate buffer solution is a 0.02 mol / l solution of NaH-PO ₄ / Na, HPO. (pH 7) containing 0.1 mol / 1 of sodium chloride. The different fractions are detected by UV (254 nm) and ion (IBF) spectrometry. The fractions thus obtained can then be optionally purified for example by SAX chromatography (strong anion exchange) according to the methods known to a person skilled in the art and in particular according to the methods described by KG Rice and RJ Linhardt, Carbohydrate Research 190, 219-233 (1989), A Larnkjaer, SH Hansen and PB Ostergaard, Carbohydrate Research, 266, 37-52 (1995) and in patent WO90 / 01501 (Example 2). The fractions are then lyophilized and then desalted on a column filled with gel such as a column of Sephadex G10 ^R gel (Pharmacia Biochemicals).

When the purification is not carried out by SAX chromatography, the lyophilisates can be optionally purified by simple or fractional precipitation according to the methods known to those skilled in the art and in particular according to the method described in patent FR2548672. In general, we operate according to the following protocol:

The lyophilized fraction to be purified is dissolved at 25 ° C in about ten volumes of distilled water. By adding methanol or ethanol, the desired oligosaccharide is precipitated by controlling its enrichment by HPLC chromatography (High Performance Liquid Chromatography). The addition of methanol or ethanol is determined according to the purity and the desired yield of said oligosaccharide. Likewise, this operation can be carried out in several successive stages starting from the initial lyophilisate solution. For this, the insolubilizing agent (methanol or ethanol) is added in small portions and the precipitate obtained is isolated after each addition. The precipitates thus prepared are analyzed by HPLC chromatography. Depending on the purity and the desired yield, the appropriate precipitate fractions are collected.

For intermediates of formula (II) for which n = 0, 1 or 2, it is preferable to start from a mixture (III) obtained by enzymatic depolymerization.

This depolymerization is carried out using heparinase I (EC 4.2.2.7), in a phosphate buffer solution of pH 7, in the presence of sodium chloride and BSA (Bovine Serum Albumin), at a temperature between 10 and 18 ° C and preferably 15 ° C for 8 to 10 days and preferably 9 days. The depolymerization is stopped for example by heating the reaction medium at 100 ° C. for 2 minutes and the mixture is recovered by lyophilization. It is preferable to use 7 IU of heparinase I for 25 g of heparin. The phosphate buffer solution generally comprises 0.05 mol / 1 of NaH ₂ PO ₄ / Na2HPO ₄ (pH 7) in the presence of 0.1 mol / 1 of sodium chloride. The BSA concentration is generally 2%.

For intermediates of formula (II) for which n = 0, 1, 2, 3 or 4, it is preferable to start from a mixture (III) obtained by depolymerization of a benzyl ester of heparin.

The heparin benzyl ester can be prepared according to the methods described in patents US5389618, EP40144, FR2548672. The esterification rate will preferably be between 50 and 100%. Preferably, it will be between 70 and 90%.

The depolymerization takes place in an aqueous medium, using an alkali metal hydroxide (lithium hydroxide, soda, potash or cesium hydroxide for example) or a quaternary ammonium hydroxide (tetrabutylammonium hydroxide for example), preferably, at a molarity between 0.1 and 0.2 mol / l, at a temperature between 40 and 80 ° C, for 5 to 120 minutes. In a preferred mode, the operation is carried out for 5 to 15 minutes, at a temperature between 60 and 70 ° C, with a 0.15 mol / l sodium hydroxide solution. The depolymerization reaction is stopped by neutralization by addition of an acid such as acetic acid. After adding 10% by weight by volume of sodium acetate, the mixture of oligosaccharides is precipitated by adding methanol, preferably 2 volumes per 1 volume of reaction medium and filtered.

According to a preferred aspect of the invention, the mixture of oligosaccharides obtained after chemical depolymerization, in the form of an aqueous solution, is enriched by ultrafiltration on membranes with an appropriate nominal cut-off threshold (Pellicon type in regenerated cellulose marketed by Millipore) ; the type of membrane being adapted as a function of the type of enriched oligosaccharides to be recovered. For the oligosaccharides (II) for which n = 0, a membrane with a threshold of nominal cutoff of 1 kDa, for oligosaccharides (II) for which n = 1, a 1 kDa or 3 kDa membrane will be used, for oligosaccharides (II) for which n = 2, a 3 kDa membrane will be used, for oligosaccharides (II) for which n = 3 or 4, a 5 kDa membrane will be used. During this operation, the permeate is recovered and the retentate rejected. Thus, the fraction of enriched product can represent from 50 to 10% of the initial oligosaccharide mixture while retaining at least 80% of the desired oligosaccharide.

For the intermediates of formula (II) for which n = 0 to 25, it is preferable to start from a mixture (III) obtained by depolymerization of a benzyl ester of sulfated hemisynthetic polysaccharide. The benzyl ester of sulfated hemisynthesis polysaccharide is prepared from sulfated hemisynthesis polysaccharides obtained from polysaccharide K5 and according to the methods described in patents WO94 / 29352 and WO96 / 14425. The conditions for esterification, depolymerization and recovery are the same as those described above for the benzyl heparin ester.

In all the above methods, the initial heparin can be of porcine, ovine, caprine or bovine origin and can come from the mucus, lungs or skins of animals. Preferably, a heparin from porcine, ovine or beef lung mucus and even more preferably from porcine mucus is used.

The oligosaccharides of formula (I) have anti-inflammatory properties and can therefore be used for the prevention or treatment of diseases linked to an inflammatory process involving the production of cytotoxic substances such as nitric oxide (NO), the form of which inducible is released in particular by neutrophils or macrophages when these migrate and are activated in a tissue. The activation, migration, adhesion and infiltration of neutrophils occurs in the ischemic tissue areas following an occlusion or spasm of an artery vascularizing this tissue. These ischemias can occur either at the cerebral level (stroke), or at the level of the myocardium (infarction myocardium), or in the lower limbs (so-called peripheral ischemia). The oligosaccharides of formula (I) can thus be used for the prevention and or the treatment of neurodegenerative diseases for which the cerebral inflammation plays a deleterious role which can lead to death among which one can cite cerebral ischaemias, cardiac ischemias (infarcts) myocardium), peripheral ischemia, trauma to the central nervous system and in particular cranial, spinal and craniospinal trauma, multiple sclerosis, neuropathic pain and peripheral neuropathy, motor neuron diseases including amyotrophic lateral sclerosis, neuro-AIDS, Alzheimer's disease, Parkinson's disease and Huntington's chorea and certain forms of osteoarthritis, particularly with joint location.

The anti-inflammatory activity of these products has been demonstrated in vivo in the NOx (nitrite and nitrate) production test induced by a lipopolysaccharide (LPS) from E. Coli according to the protocol described by M. YAMASHITA et al., Eur. J. Pharmacol, 338, 2, 151-158 (1997) or J.E. SHELLITO et al. Am. J. Respir. Cell Mol. Biol., 13, 1, 45-53 (1995).

Male CD1 mice (Charles River, 25-35g) are injected at T0 by intravenous bolus 0.5 mg / kg of the oligosaccharide, at T + 15 minutes, subcutaneously 1 or 2 mg / kg of the oligosaccharide. At T + 30 minutes, 100 mg / kg of lipopolysaccharide (LPS) from E. Coli (Sigma L3129, serotype 0127: B8). At T + 3 hours, 1 or 2 mg / kg of the oligosaccharide is again injected subcutaneously. At T + 5 hours 30 minutes, a blood sample is recovered by eye puncture and the NOx (nitrite and nitrate) concentrations in the plasma are determined with the Griess colorimetric method after reduction of the nitrate to nitrite by nitrate reductase as follows: 12 μl of the plasma sample are mixed with 88 μl of deionized water and incubated in the dark for 1 hour at room temperature with 40 μl of phosphate buffer (0.31 M, pH 7.5), 20 μl of β- NADPH (nicotinamide adenine dinucleotide phosphate reduced) (0.86 mM), 20 μl of FDA (flavin adenine dinucleotide) (0.11 mM) and 20 μl of nitrate reductase (2U / ml) (Boehringer Mannheim). 10 μl of ZnSO ₄ (1M) are added to precipitate the proteins and after mixing, the samples are centrifuged at 20,000 g for 5 minutes. Finally, 50 μl of the supernatant are incubated for 10 minutes at room temperature with 100 μl of the Griess reagent (1% sulfanilamide in a phosphoric acid / naphthethylenediamine 0.1% mixture in deionized water (V / V)). The optical densities are read at 540 nm with a microplate spectrophotometer; each point being determined twice. KNO ₃ and NaNO ₂ are used as standard for the colorimetric method.

In this test, the oligosaccharides according to the invention more than 50% inhibit the formation of NOx.

Among the preferred oligosaccharides of formula (I), mention may in particular be made of oligosaccharides for which:

- n is equal to 0, Ri and R ₆ represent a radical SO ₃ Na and M is sodium and the mixture of its diastereoisomers - n is equal to 1, Ri, R ₂ , R ₃ , R ₅ , R ₆ , represent a radical SO ₃ Na, R ₄ represents a hydrogen atom and M is sodium and the mixture of its diastereoisomers

- n is equal to 2, Ri, R ₂ , R ₃ , R ₅ , R ₆ represent a radical SO ₃ Na, R represents a hydrogen atom and M is sodium and the mixture of its diastereoisomers.

- n is equal to 2, R ,, R-, R ₃ , R ₆ , represent an SO ₃ Na radical, R ₅ represents a hydrogen atom or an SO ₃ Na radical, R ₄ represents a hydrogen atom and M is sodium and the mixture of its diastereoisomers (derivative 1.6 anhydro ΔIs-Is-IIs).

The following examples are representative of the preparation of the oligosaccharides of formula (I) and of the intermediates.

In these examples the meanings of the abbreviations are as follows: ΔIs: (4-deoxy-2-O-sulfo-α-L-threo-hex-enopyranosyluronic acid) - (l → 4) -2-deoxy- 2-sulfoamino-6- <9-sulfo-α-D- glucopyranose, tetrasodium salt or ΔUA / .2S- (l → 4) -α-D-GlcN /? 2S6S

Is: (2-sulfo-α-L-idop ranosyluronic) - (l → 4) -2-deoxy-2-sulfoamino-6-O- sulfo-α-D-glucopyranose, tetrasodium salt or α-L -IdoAp2S- (l → 4) -α-D- GlcN / .2S6S

They: (α-L-idopyranosyluronic acid) - (l → 4) -2-deoxy-2-sulfoamino-6-O-sulfo-α-D- glucopyranose, trisodium salt or α-L-IdoA .- ( l → 4) -α-D-GlcN .2S6S

IIIs: (2-sulfo-α-L-idopyranosyluronic acid) - (l → 4) -2-deoxy-2-sulfoamino-α-D- glucopyranose, trisodium salt or α-L-IdoA .2S- (l → 4) -α-D-GlcN /? 2S

IdoAp: idopyranosyluronic acid

GlcN />: 2-deoxy-2-aminoglucopyranose

ΔUap: 4-deoxy-α-L-threo-hex-enopyranosyluronic acid

S: sulfate

EXAMPLES OF PREPARATION OF MIXTURES OF FORMULA (II)

EXAMPLE A Preparation of the oligosaccharides of formula (II) for which n = 0, 1 and 2 by enzymatic depolymerization and separation

Dissolve 25 g of heparin in 250 ml of a phosphate buffer solution containing 0.05 mol / 1 NaH ₂ PO ₄ / Na ₂ HPO ₄ (pH = 7), 0.2 mol / 1 of sodium chloride and 2% BSA (Bovine Serum Albumin). 7 IU of heparinase I (EC 4.2.2.2.7) are introduced into the mixture and the solution obtained is cooled to 15 ° C. and then kept at this temperature for the entire duration of the depolymerization reaction. The progress of the reaction is followed by staggered samples of aliquots and analyzed by gel permeation chromatography. After 9 days, the enzymatic reaction is stopped by heating the reaction medium at 100 ° C for two minutes. The cooled mixture is then lyophilized. A mixture of oligosaccharides (III) is thus obtained.

The mixture of oligosaccharides (III) obtained is then chromatographed according to the following method: The chromatography is carried out on columns filled with polyacrylamide-agarose gel known under the name Ultrogel ACA 202 and the mixture is eluted with a solution containing a buffer phosphate (0.02 mol / 1 NaH ₂ PO / Na ₂ HPO ₄ ) pH = 7 and 0.1 mol / 1 of sodium chloride. Detection is carried out by UV (254 nm) and ion (IBF) spectrometry. The products can optionally be purified by SAX chromatography (strong anion exchange) or by fractional precipitation according to the method described in patent FR 2548672. The fractions of recovered product are lyophilized and then desalted on a column filled with sephadex G10 ^R gel (Pharmacia Bioche icals ).

By this method, 3 g of disaccharide Is is obtained, 1100 mg of a mixture of hexasaccharide typically containing 55% of ΔIs-Is-Is derivative, 35% of ΔIs-Is-IIs and 10% of ΔIs-Is- IIIs. This latter mixture can be purified according to methods known to a person skilled in the art in order to separate each of the constituents thereof or used as such for the transformation into 1.6 anhydro derivatives of formula (I). It should be noted that during this transformation the hexasaccharide ΔIs-Is-IIIs cannot lead to the formation of compounds of formula (I).

EXAMPLE B Preparation of the oligosaccharides of formula (II) for which n = 0, 1, 2, 3 or 4 by depolymerization of the benzyl heparin ester and separation

a - Preparation of the benzyl ester of heparin

The heparin benzyl ester is prepared according to Example 3 of US Patent 5,389,618.

b- Depolymerization Dissolve 100 g of heparin benzyl ester in 1.9 l of demineralized water. The mixture is brought to 60 ° C. with stirring. After obtaining a homogeneous solution, approximately 35 ml of a 23% sodium hydroxide solution are introduced all at once. After 10 minutes of reaction, the solution is then cooled and neutralized with 80 ml of an approximately 2N acetic acid solution. To this solution, 10% by weight / volume of sodium acetate is added. The mixture of oligosaccharides is precipitated by the addition of approximately 2 volumes of methanol. The precipitate is isolated by filtration, washed with methanol twice and then dried under reduced pressure at 50 ° C. After drying, 73.8 g of a mixture of oligosaccharides (II) are obtained.

c- Enrichment in oligosaccharide for which n = 1

Dissolve 30 g of the mixture of oligosaccharides obtained previously in approximately 35 volumes of water. This solution is ultrafiltered on a 3 kDa membrane (Pellicon). When 600 ml of permeate have been withdrawn, the retentate is diluted with 500 ml of water. The operation is continued until 450 ml of additional permeate are withdrawn. The two permeate fractions are combined and then concentrated to dryness under reduced pressure. 6.1 g of a yellowish white solid are obtained. Analysis of the solid by gel permeation chromatography indicates that it contains approximately 30% of oligosaccharide of formula (II) for which n = 1.

d - Fractionation of mixtures of ultrafiltered oligosaccharides

The enriched mixture is fractionated on columns filled with polyacrylamide-agarose gel known under the name Ultrogel ACA 202 (4 columns in series with a diameter of 10 cm and a height of 50 cm are used). 5 g of the mixture enriched by ultrafiltration are dissolved in 25 ml of water and then eluted with a 0.2 mol / l solution of sodium chloride at the speed of 5 ml / min. 25 ml fractions are collected at the bottom of the column. The detection of the products is carried out by UV (254 nm) and ion (IBF) spectrometry. The product fractions for which n = 1 are recovered, lyophilized and then desalted on a column filled with Sephadex G10 gel. After lyophilization, lg of tetrasaccharide is obtained, typically containing 70% of ΔIs-Is derivative of formula II (R ,, R ₂ , R ₃ , R ₅ , R ₆ = SO ₃ Na; ^ = H and M = Na). The ΔIs-Is derivative can optionally be purified by SAX chromatography (strong anion exchange) or according to a preferential aspect by fractional precipitation according to the method described in patent FR 2548672.

EXAMPLE 1

5 ml of a 0.0063 mol / l sodium hydroxide solution are introduced into a reactor maintained at 66 ° C. The pH of the solution is then measured and taken as the target value (pH = 11.35). With stirring, 30 mg of the oligosaccharide of formula (II) for which n is equal to 0, Ri and R ₆ represent an SO ₃ Na radical and M is sodium are added at once. The pH is then regulated and maintained at pH 11.35 by continuous addition of a 0.5 mol / l sodium hydroxide solution. After 10 hours, the addition of sodium hydroxide is stopped and the reaction mixture is cooled to 25 ° C. The pH of the solution is then brought back to between 6 and 7 by addition of Amberlite IR120 resin. The mixture is filtered on a Whatman GF / B membrane and then concentrated to dryness under reduced pressure (2.7 kPa), at a temperature in the region of 25 ° C. The product is taken up with 0.5 ml of distilled water and then lyophilized. 29 mg of a mixture of diastereoisomers of the oligosaccharide of formula (I) are obtained for which n is equal to 0, Ri and R ₆ represent an SO ₃ Na radical and M is sodium [(4-deoxy-2 acid -O-sulfo-α- - threo-hex-4-enopyranosyluronic- (1 → 4) - 1, 6-anhydro-2-deoxy-2-sulfoamino-β-D- mannopyranose, trisodium salt): Proton spectrum in D ₂ O, 400MHz, T = 298K, δ in ppm: 3.15 (1H, s, H2), 3.75 (2H, m, H6 and H3), 3.88 (1H, m, H4), 4 , 20 (1H, d, J = 8Hz, H6), 4.22 (1H, t, J = 5Hz, H3 '), 4.58 (1H, m, H2'), 4.75 (1H, m, H5), 5.53 (1H, s, Hl), 5.60 (1H, dd, J = 6 and 1Hz, Hl '), 6.03 (1H, d, J = 5Hz, H4'); (4-deoxy-2-0-sulfo-α- -thréo-hex-4-enopyranosyluronique- (1 → 4) - 1, 6-anhydro-2-deoxy-2-sulfoamino-β-D- glucopyranose, salt trisodium): Proton spectrum in D ₂ O, 400MHz, T = 298K, δ in ppm: 3.34 (1H, dd, J = 7 and 2Hz, H2), 3.72 (1H, t, J = 8Hz, H6), 3.90 (1H, m, H3), 4.03 (1H, s, H4), 4.20 (1H, d, J = 8Hz, H6), 4.23 (1H, t, J = 5Hz, H3 '), 4.58 (1H, m, H2'), 4.78 (1H, m, H5), 5.50 (1H, s, Hl), 5.60 (1H, dd, J = 6 and 1Hz, Hl '), 6.03 (1H, d, J = 5Hz, H4')]. EXAMPLE 2

33.3 ml of a 0.0063 mol / l sodium hydroxide solution are introduced into a reactor maintained at 62 ° C. The pH of the solution is then measured and taken as the target value (pH = 1.15). With stirring, 200 mg of the oligosaccharide of formula (II) for which n is equal to 1, Ri, R, R ₃ , R ₅ and R ₆ represent an SO Na radical, R_ι represents an atom d, are added at once. 'hydrogen and M is sodium. The pH is then regulated and maintained at pH 11.15 by continuous addition of a 0.5 mol / l sodium hydroxide solution. After 12 hours, the addition of sodium hydroxide is stopped and the reaction mixture is cooled to 25 ° C. The pH of the solution is then brought back to between 6 and 7 by addition of Amberlite IR120 resin. The mixture is filtered on a Whatman GF / B membrane and then concentrated to dryness under reduced pressure (2.7 kPa), at a temperature in the region of 25 ° C. The product is taken up in 3 ml of distilled water and then lyophilized. 230 mg of the oligosaccharide of formula (I) are thus obtained for which n is equal to 1, Ri, R ₂ , R ₃ , R ₅ , R ₆ , represent an SO ₃ Na radical, R represents a hydrogen atom and M is sodium, in the form of a mixture of diastereoisomers [(4-deoxy-2-Osulfo-α- L-threo-hex-4-enopyranosyluronique- (1 ^ 4) -2-deoxy-2-sulfoamino- 6-O-sulfo-α-D- glucopyranosyl- (1 -> 4) -acid 2-Osulfo-α- -idopyranosyluronic - (1 —.4) - 1, 6- anhydro-2-deoxy-2-sulfoamino- β-D-mannopyranose, heptasodium salt): Proton spectrum in D _: O, 400MHz, T = 298K, δ in ppm: 3.15 (IH, s, H2), 3.25 (IH, m, H2 " ), 3.60 (IH, m, H3 "), between 3.70 and 4.70 (14H, massive, H3 / H4 / H6, H2 '/ H3' / H4 '/ H5', H4" / H5 " / H6 ", H2"'/ H3 "'), 4.75 (IH, m, H5), between 5.20 and 5.40 (2H, m, Hl 'and Hl"), 5.45 (IH, m, Hl '"), 5.56 (IH, m, Hl), 5.94 (IH, d, J = 5Hz, H4); (4-deoxy-2-O-sulfo-α-L-threo acid -hex-4-enopyranosyluronique - (1 → 4) -2-deoxy-2-sulfoamino-6-0- sulfo-α-D-glucopyranosyl- (l → 4) acid -2-O-sulfo-α-L- IDOP yranosyluronic - (1 → 4) - 1.6-anhydro-2-deoxy-2-sulfoamino-β-D-glucopyranose, heptasodium salt): Proton spectrum in D ₂ O, 400 MHz, T = 298K, δ in ppm : 3.25 (1H, m, H2 "), 3.42 (1H, dd, J = 4 and 1Hz, H2), 3.60 (1H, m, H3"), between 3.70 and 4.70 (14H, massive, H3 / H4 / H6, H2 '/ H3' / H47H5 ', H4 "/ H5" / H6 ", H2" VH3 "'), 4.75 (IH, m, H5), between 5, 20 and 5.40 (2H, m, Hl 'and Hl "), 5.45 (1H, m, Hl"'), 5.52 (1H, m, Hl), 5.94 (1H, d, J = 5Hz, H4)]. EXAMPLE 3

16.7 ml of a 0.0063 mol / l sodium hydroxide solution are introduced into a reactor maintained at 62 ° C. The pH of the solution is then measured and taken as the target value (pH = 1 1.7). With stirring, 100 mg of the oligosaccharide of formula (II) for which n is equal to 2, Ri, R ₂ , R, R ₅ and R ₆ represent an SO ₃ Na radical, R represents an atom, are added at once. hydrogen and M is sodium. The pH is then regulated and maintained at pH 11.7 by continuous addition of a 0.5 mol / l sodium hydroxide solution. After 10 hours, the addition of sodium hydroxide is stopped and the reaction mixture is cooled to 25 ° C. The pH of the solution is then brought back to between 6 and 7 by addition of Amberlite IR120 resin. The mixture is filtered on a Whatman GF / B membrane and then concentrated to dryness under reduced pressure (2.7 kPa), at a temperature in the region of 25 ° C. The product is taken up in 3 ml of distilled water and then lyophilized. 108 mg of the oligosaccharide of formula (I) are thus obtained for which n is equal to 2, Ri, R ₂ , R ₃ , R ₅ , R ₆ represent an SO ₃ Na radical, R represents a hydrogen atom and M is sodium, in the form of a mixture of diastereoisomers. The sugars constituting the hexasaccharides are noted from A to F, A being the 1,6-anhydro residue and F the unsaturated uronic acid residue, [(4-deoxy-2-O-sulfo-α-L-threo-hex- 4-enopyranosyluronic - (1 → 4) - 2-deoxy-2-sulfoamino-6-0-sulfo-α-D-glucopyranosyl- (l— .4) - 2-0- sulfo-α-L-idopyranosyluronic acid - (1 -> 4) - 2-deoxy-2-sulfoamino-6- <9-sulfo-α-D- glucopyranosyl- (l → 4) -acid 2-0-sulfo-α-L-idopyranosyluronique- (l— .4) - 1,6- anhydro-2-deoxy-2-sulfoamino-β-D-mannopyranose, undecasodium salt): Proton spectrum in D ₂ O, 600MHz, T = 298K, δ in ppm: 3.15 (IH, s, H2 (A)), 3.25 (2H, m,

H2 (C + E)), 3.60 (2H, m, H3 (C + E)), between 3.65 and 4.50 (19H, massive, H2 (B + D) / H3 (A + B + D + F) / H4 (A + B + C + D + E) / H5 (C + E) / H6 (A + C + E)), 4.60 (IH, s, H2 (F)), 4 , 80 (3H, m, H5 (A + B + D), 5.18 (IH, s, H1 (D)), 5.30 (IH, s, H1 (B)), 5.34 (IH, d, H1 (C)), 5.36 (IH, d, H1 (E)), 5.46 (IH, s, H1 (F)), 5.57 (IH, s, H1 (A)), 5.95 (1H, d, J = 5Hz, H4 (F)); (4-deoxy-2-O-sulfo-α- -threo-hex-4- enopyranosyluronic acid- (l → 4) -2-deoxy -2-sulfoamino-6-O-sulfo-α-D-glucopyranosyl- (1 → 4) -acid 2-0-sulfo-α-L-idopyranosyluronic - (1 - .4) -2-deoxy-2-sulfoamino -6- 0-sulfo-α-D-glucopyranosyl- (1 → 4) -2-O-sulfo-α-L-idopyranosyluronic acid- (1—> 4) -1.6-anhydro-2-deoxy-2-sulfoamino-β-D-glucopyranose, undecasodium salt): Proton spectrum in D _: O, 600MHz, T = 298K, δ in ppm: 3.25 (2H, m, H2 (C + E)), 3.42 (1H, m, H2 (A)), 3.60 (2H, m, H3 (C + E)), between 3.65 and 4.50 (19H, massive, H2 (B + D) / H3 (A + B + D + F) / H4 (A + B + C + D + E) / H5 (C + E) / H6 (A + C + E)), 4.60 (IH, s, H2 (F)), 4.80 (3H, m, H5 (A + B + D), 5.18 (IH, s, H1 (D) ), 5.31 (1H, s, H1 (B)), 5.34 (1H, d, H1 (C)), 5.36 (1H, d, H1 (E)), 5.46 (1H, s, H1 (F)), 5.52 (IH, s, H1 (A)), 5.95 (IH, d, J = 5Hz, H4 (F))].

EXAMPLE 4

4 ml of a 0.0316 mol / l sodium hydroxide solution are introduced into a reactor maintained at 62 ° C. The pH of the solution is then measured and taken as the target value (pH = 1 1.8). With stirring, 100.8 mg of a mixture of oligosaccharides of formula (II) for which n is equal to 2 comprising 55% of derivative ΔIs-Is-Is (Ri, R ₂ , R ₃ , R _{5) are added at once} and R represent an SO ₃ Na radical, Ri represents a hydrogen atom and M is sodium), 35% of ΔIs-Is-IIs (Ri, R ₂ , R ₃ , and R _Ô represent an SO ₃ Na radical, R ₅ represents either an SO ₃ Na radical or a hydrogen atom, R represents a hydrogen atom and M is sodium) and 10% of ΔIs-Is-IIIs (Ri, R, R ₃ , R ₅ and R ₆ represent an SO ₃ Na radical, R * represents a hydrogen atom and M is sodium, the SO ₃ M function of carbon C6 being replaced by a hydrogen). The pH is then regulated and maintained at pH 11.8 by continuous addition of a 0.5 mol / l sodium hydroxide solution. After 11 hours, the addition of sodium hydroxide is stopped and the reaction mixture is cooled to 25 ° C. The pH of the solution is then brought back to between 6 and 7 by addition of Amberlite IR120 resin. The mixture is filtered on a Whatman GF / B membrane and then concentrated to dryness under reduced pressure (2.7 kPa), at a temperature in the region of 25 ° C. The product is taken up in 1.5 ml of distilled water and then lyophilized. 110 mg of a mixture of oligosaccharides of formula (I) are thus obtained for which n is equal to 2, containing in particular the derivative 1.6 anhydro ΔIs-Is-Is (Ri, R ₂ , R ₃ , R ₅ , R ₆ represent an SO ₃ Na radical, R ₄ represents a hydrogen atom and M is sodium) and the 1.6 anhydro derivative ΔIs-Is-IIs (Ri, R ₂ , R, R ₆ , represent an SO ₃ radical Na, R ₅ represents either an SO ₃ Na radical or a hydrogen atom, R ₄ represents a hydrogen atom and M is sodium). HPLC analysis (High Performance Liquid Chromatography) in ion pair mode makes it possible to follow the transformation into derivatives of formula (I). In this case, the HPLC assay shows that the transformation is carried out for the ΔIs-Is-Is, ΔIs-Is-IIs derivatives.

EXAMPLE 5

8.6 ml of a 0.025 mol / l lithium hydroxide solution is introduced into a reactor maintained at 66 ° C. The pH of the solution is then measured and taken as the target value (pH = 11.68). With stirring, 50 mg of the oligosaccharide of formula (II) for which n is equal to 0, Ri and R ₆ represent an SO ₃ Na radical and M is sodium are added at once. The pH is then regulated and maintained at pH 11.68 by continuous addition of a solution of lithium hydroxide at 0.466 mol / l. After 8 hours, the addition of lithium hydroxide is stopped and the reaction mixture is cooled to 25 ° C. HPLC analysis (High Performance Liquid Chromatography) in ion pair mode makes it possible to follow the transformation into a derivative of formula (I) for which n is equal to 0, R] and R ₆ represent an SO ₃ Na radical and M is sodium or lithium. In this case, the HPLC assay shows that the transformation is carried out at 100%. The yield by external calibration is 81.2%.

EXAMPLE 6

8.3 ml of a 0.0063 mol / l potassium hydroxide solution are introduced into a reactor maintained at 66 ° C. The pH of the solution is then measured and taken as the target value (pH = 11.1). With stirring, 50 mg of the oligosaccharide of formula (II) for which n is equal to 0, R and R ₆ represent an SO ₃ Na radical and M is sodium are added at once. The pH is then regulated and maintained at pH 11.1 by continuous addition of a 0.515 mol / l potassium hydroxide solution. After 24 hours, the addition of potassium hydroxide is stopped and the reaction mixture is cooled to 25 ° C. HPLC analysis (High Performance Liquid Chromatography) in ion pair mode makes it possible to follow the transformation into a derivative of formula (I) for which n is equal to 0, Ri and R ₆ represent an SO ₃ Na radical and M is sodium or potassium. In this case, the dosage HPLC shows that the transformation is carried out at 100%. The yield by external calibration is 75.6%.

EXAMPLE 7

8.3 ml of a 0.0063 mol / l cesium hydroxide solution are introduced into a reactor maintained at 66 ° C. The pH of the solution is then measured and taken as the target value (pH = 10.75). With stirring, 50 mg of the oligosaccharide of formula (II) for which n is equal to 0, R is added at once _. and R ^ represent an SO ₃ Na radical and M is sodium. The pH is then regulated and maintained at pH 10.75 by continuous addition of a solution of cesium hydroxide at 0.476 mol / l. After 20 hours, the addition of cesium hydroxide is stopped and the reaction mixture is cooled to 25 ° C. HPLC analysis (High Performance Liquid Chromatography) in ion pair mode makes it possible to follow the transformation into a derivative of formula (I) for which n is equal to 0, Ri and R ₆ represent an SO ₃ Na radical and M is sodium or cesium. In this case, the HPLC assay shows that the transformation is 90.3% complete. The yield by external calibration is 73%.

EXAMPLE 8

8.3 ml of a 0.0063 mol / l tetrabutylammonium hydroxide solution are introduced into a reactor maintained at 66 ° C. The pH of the solution is then measured and taken as the target value (pH = 10.95). With stirring, 50 mg of the oligosaccharide of formula (II) for which n is equal to 0, R] and R ^ are added an SO ₃ Na radical and M is sodium are added at once. The pH is then regulated and maintained at pH 10.95 by continuous addition of a solution of tetrabutylammonium hydroxide at 0.521 mol / 1. After 16 hours, the addition of cesium hydroxide is stopped and the reaction mixture is cooled to 25 ° C. HPLC analysis (High Performance Liquid Chromatography) in ion pair mode makes it possible to follow the transformation into a derivative of formula (I) for which n is equal to 0, Ri and R ₆ represent an SO ₃ Na radical and M is sodium or tetrabutylammonium. In this case, the HPLC assay shows that the transformation is carried out at 96.7%. The yield by external calibration is 65%. The medicaments according to the invention comprise, as active ingredient, at least one oligosaccharide of formula (I) or a mixture of oligosaccharides of formula (I), in the form of a composition in which it is associated with any other pharmaceutically compatible product. , which may be inert or physiologically active. The medicaments according to the invention can be used by the intravenous, subcutaneous, oral, rectal, topical or pulmonary (inhalation) route.

The sterile compositions for intravenous or subcutaneous administration are generally aqueous solutions. These compositions can also contain adjuvants, in particular wetting agents, isotonizers, emulsifiers, dispersants and stabilizers. Sterilization can be done in several ways, for example by aseptic filtration, by incorporating sterilizing agents into the composition, by irradiation. They can also be prepared in the form of sterile solid compositions which can be dissolved at the time of use in sterile water or any other sterile injectable medium.

As solid compositions for oral administration, tablets, pills, powders (gelatin capsules, cachets) or granules can be used. In these compositions, the active principle is mixed with one or more inert diluents, such as starch, cellulose, sucrose, lactose or silica, under a stream of argon. These compositions can also include substances other than diluents, for example one or more lubricants such as magnesium stearate or talc, an agent promoting oral absorption, a colorant, a coating (dragees) or a varnish.

As liquid compositions for oral administration, use may be made of pharmaceutically acceptable solutions, suspensions, emulsions, syrups and elixirs containing inert diluents such as water, ethanol, glycerol, vegetable oils or oil paraffin. These compositions can include substances other than diluents, for example wetting, sweetening, thickening, flavoring or stabilizing products. The compositions for rectal administration are suppositories or rectal capsules which contain, in addition to the active product, excipients such as cocoa butter, semi-synthetic glycerides or polyethylene glycols.

The compositions for topical administration can be, for example, creams, lotions, eye drops, mouthwashes, nasal drops or aerosols.

The doses depend on the desired effect, on the duration of the treatment and on the route of administration used; they are generally between 0.5 mg and 10 mg per kg per day by subcutaneous route, ie 3 to 60 mg per day for an adult of 60 kg.

In general, the doctor will determine the appropriate dosage based on age, weight and all other factors specific to the subject to be treated.

The invention also relates to the method for preventing or treating diseases linked to an inflammatory process involving the production of cytotoxic substances such as nitrite oxide (NO). The oligosaccharides of formula (I) can thus be used for the prevention and / or the treatment of neurodegenerative diseases for which the cerebral inflammation plays a deleterious role which can lead to death among which one can cite ischaemias of the central nervous system, cerebral ischaemia, ischemia of the retina and cochlea, cardiac ischemia (myocardial infarction), peripheral ischaemia, trauma of the central nervous system and in particular head, spinal and craniospinal trauma, trauma to the retina and cochlea, multiple sclerosis, neuropathic pain and peripheral neuropathy, motor neuron diseases including amyotrophic lateral sclerosis, neuro-AIDS, Alzheimer's disease, Parkinson's disease and Huntington's chorea and certain forms osteoarthritis, especially with joint location.

Claims

1 - Oligosaccharides of formula:

in which n is an integer from 0 to 25, Ri, R ₃ , * and R ₅ , identical or different, represent a hydrogen atom or an SO ₃ M radical, R ₂ and R ₆ , identical or different, represent a hydrogen atom or SO ₃ M or COCH ₃ and M is sodium, calcium, magnesium or potassium, a mixture of these oligosaccharides and their diastereoisomers.

2 - Oligosaccharides of formula (I) according to claim 1 for which 1 ^ represents a hydrogen atom, a mixture of these oligosaccharides and their diastereoisomers.

3 - Oligosaccharides of formula (I) according to one of claims 1 or 2 for which n is an integer from 0 to 10, a mixture of these oligosaccharides and their diastereoisomers.

4 - Oligosaccharides of formula (I) according to one of claims 1 or 2 for which n is an integer from 0 to 6, a mixture of these oligosaccharides and their diastereoisomers.

5 - Oligosaccharides of formula (I) according to one of claims 1 or 2 for which n is an integer from 1 to 6, a mixture of these oligosaccharides and their diastereoisomers. 6 - Process for the preparation of oligosaccharides of formula (I) according to claim 1 characterized in that an alkali metal hydroxide or quaternary ammonium hydroxide is reacted with oligosaccharides of formula:

in which n is an integer from 0 to 25, Ri, R ₃ , R ₄ and R ₅ , identical or different, represent a hydrogen atom or an SO ₃ M radical, R ₂ and R ₆ , identical or different, represent a hydrogen atom or an SO M or COCH ₃ radical and M is sodium, calcium, magnesium or potassium, or a mixture of these and isolates the oligosaccharides or their mixtures.

7 - Process according to claim 6 characterized in that the reaction is carried out in an aqueous medium, at a temperature of 40 to 80 ° C and at a pH of 10 to 13.

8 - Method according to one of claims 6 or 7 characterized in that an aqueous solution of 1 to 5% of alkali metal hydroxide or quaternary ammonium is used.

9 - Method according to one of claims 6 to 8 characterized in that the reaction is carried out at a temperature of 60 to 70 ° C.

10 - Method according to one of claims 6 to 9 characterized in that the reaction pH is from 11 to 12.5.

11 - Method according to claims 6 to 10 characterized in that the alkali metal hydroxide or quaternary ammonium is sodium hydroxide, potassium hydroxide, lithium hydroxide, cesium or tetrabutylammonium hydroxide. 12 - Pharmaceutical compositions containing as active ingredient at least one oligosaccharide according to claim 1.

13 - Pharmaceutical compositions containing as active ingredient at least one oligosaccharide according to one of claims 1 to 5.

14 - Use of oligosaccharides of formula (I) according to one of claims 1 to 5 for the preparation of a medicament useful for the prevention or treatment of diseases linked to an inflammatory process involving the production of nitrite oxide (NO).

15 - Use of the oligosaccharides of formula (I) according to claim 14 for the preparation of medicaments useful for the prevention and treatment of cerebral, cardiac or peripheral vascular ischemia, osteoarthritis, trauma of the central nervous system, head trauma, spinal and craniospinal, multiple sclerosis, neuropathic pain and peripheral neuropathy, motor neuron diseases, amyotrophic lateral sclerosis, neuro-AIDS, Alzheimer's disease, Parkinson's disease and Huntington's chorea.